Study On The Removal Mechanism Of Single Crystal Silicon By Three-body Polishing With Diamond Abrasive Based On Molecular Dynamic

As a brittle and hard nano-material,monocrystalline silicon has the disadvantages of high brittleness,low plasticity and microcrack at room temperature,which hinders the research on the processing mechanism of brittle and hard materials.On the other hand,monocrystalline silicon has excellent photoelectric properties.As a semiconductor material,it has important research significance.At present,there is no clear explanation for the formation of damage and material removal mechanism in the polishing process of monocrystalline silicon,and the change of crystal internal structure cannot be dynamically observed by experimental research method.In this paper,the three-dimensional model of monocrystalline silicon polishing process is established by molecular dynamics method.Combined with the means of theoretical analysis,the generation and change process of monocrystalline silicon internal damage in the polishing process are analyzed,and the influence of processing parameters on the damage is clarified.Firstly,the molecular dynamics model and theoretical analysis model of polishing ideal monocrystalline silicon with single abrasive particle are established,the influence of different abrasive particle size on processing is studied,and the effects of different polishing depth on the coordination number of silicon atoms in monocrystalline silicon workpiece,stress change,damage evolution,as well as the changes of temperature and potential energy in the measurement area during polishing are discussed.This paper attempts to verify the influence of polishing depth on the processing quality of monocrystalline silicon through simulation and theoretical research.Secondly,since monocrystalline silicon is not natural and ideal without defects,a monocrystalline silicon with different sizes of inclusions in single abrasive polishing is established to explore the influence of different sizes of inclusions on monocrystalline silicon processing;Then the coordination number,phase transformation,dislocation,temperature and potential energy of polishing area in the machining process are analyzed.Finally,combined with the interaction of multi abrasive particles in the polishing process,the model of double abrasive particle polishing monocrystalline silicon is established to study the effects of double abrasive particle polishing on phase transformation,friction,surface morphology,temperature and potential energy in the measurement area,mainly the effects of different abrasive particle spacing.